mirror of
https://github.com/klzgrad/naiveproxy.git
synced 2024-11-28 00:06:09 +03:00
44 lines
1.3 KiB
C++
44 lines
1.3 KiB
C++
// Copyright 2016 The Chromium Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#ifndef BASE_BIT_CAST_H_
|
|
#define BASE_BIT_CAST_H_
|
|
|
|
#include "base/compiler_specific.h"
|
|
|
|
#if !HAS_BUILTIN(__builtin_bit_cast)
|
|
#include <string.h>
|
|
#include "base/template_util.h"
|
|
#endif
|
|
|
|
// This is C++20's std::bit_cast<>().
|
|
// It morally does what `*reinterpret_cast<Dest*>(&source)` does, but the cast/deref pair
|
|
// is undefined behavior, while bit_cast<>() isn't.
|
|
template <class Dest, class Source>
|
|
#if HAS_BUILTIN(__builtin_bit_cast)
|
|
constexpr
|
|
#else
|
|
inline
|
|
#endif
|
|
Dest
|
|
bit_cast(const Source& source) {
|
|
#if HAS_BUILTIN(__builtin_bit_cast)
|
|
// TODO(thakis): Keep only this codepath once nacl is gone or updated.
|
|
return __builtin_bit_cast(Dest, source);
|
|
#else
|
|
static_assert(sizeof(Dest) == sizeof(Source),
|
|
"bit_cast requires source and destination to be the same size");
|
|
static_assert(base::is_trivially_copyable<Dest>::value,
|
|
"bit_cast requires the destination type to be copyable");
|
|
static_assert(base::is_trivially_copyable<Source>::value,
|
|
"bit_cast requires the source type to be copyable");
|
|
|
|
Dest dest;
|
|
memcpy(&dest, &source, sizeof(dest));
|
|
return dest;
|
|
#endif
|
|
}
|
|
|
|
#endif // BASE_BIT_CAST_H_
|